Construction of sheet-m etal pipes



(No Model.)

J. 1-". WEITZEL. CONSTRUCTION 0 SHEET METAL PIPES. No. 592,459.

Patented Oct. 26,1897.

[brag/021 age Wd To all whom it may conceive ance with r'nyimproved construction. .2 is an enlarged end view of the same. '3iis a sectional detail View of the locking- UNiTnD STATES PATENT OFFICE.

JACOB F. lVEITZEL, OF LUDLOiV, KENTUCKY.

CONSTRUCTION OF SHEET-METAL PIPES.

SPECIFICATION forming part of Letters Patent No. 592,459, dated October 26,. 1897. Application filed January 11, 1397- Serial No. 618,768. (No model.)

Be it known that I, JACOB F. WEITZEL, a

citizen of the United States, and a residentof Ludlow, Kenton county. State of Kentucky, have invented certain new and useful Improvementsin the Construction of Sheet- Metal Pipes; and I do declare the following to be a clear, full, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, attention being called to the accompanying drawings, with the referencenumerals marked thereon, which form a part of this specification.

This invention relates to improvements in the construction of sheet-metal pipes for all purposes, such as pipes for conductors, downspouts, exhaust-pipeaand for heating, ventilating, or dustscollecting systems. It relates particularly to improvements in the I been devised to overcome these defects and imperfections form the subject of this invention. .This latter is fully described in the following specification and pointed out in the claims at the end thereof, the construction being also illustrated in the accompanying drawings, in which v Figure 1 shows; in a perspective elevation a length'of such pipe constructed in accord- Fig. Fig.

scam, and Fig. 4 shows end of sheet before its edges are connected to form the pipe.

The profile or cross-section of this pipe should be such as to contain a number of sides and corners and is therefore polygonal.

the drawings an octagonal shape has been selooted, of which 6 are the sides and 7the corners, the latter formed where such sides join. The edges of the sheet which forms the pipe are connected by'an ordinary lock-seam 8.

Formerly the pipe-sections were then twisted eration.

by prevented, and I further improve and longitudinally, whereby the sides and corners assumed the spiral shape shown.

In the former patent the seam was located between two of the corners 7 7, which location seemed to be a very ill-chosen one, inasmuch as during the twisting operation the seam had a constant tendency to open. This tendency was caused by the fact that no provision had been made to take'care of any surplus metal, such surplus arising from a narrowing which the sides would experience during the twisting ofthe pipe. This difficulty has been overcome by having the sides formed concave by running the pipes through suitable forming devices, and which form,by

breaking the resistance of the straight sides,

permitted them to continue to yield farther in the same direction during the twisting op- The opening of the seam was therestrengthen the latter bylocating it at one. of the corners, where by reason of the formation of such corner the metal has more sta-- bility and stiffness. The seam is further secured against opening by the concave sides;

whereby an abutment is formed on the inside, as shown at 9 in Fig. 3, by one of the parts which come together when'forming the seam and against which the extreme outer edge 1 of this other part bears, and the interacting contact of which two parts at this point prevents them from slipping away from each other. has, however, other important advantages which make its application highly desirable. It aifords the pipe a possibility to expand to prevent it from bursting where such may. occur-as, for instance, when such pipes are used to carry water, as is the case in downspouts, which are liable to freeze up in winter.

Another result produced by this construc tion is the artistic effect due to the contrast of light and shadow between the projecting edges 7 and the hollow sides 6 between them. This is'of no mean importance where such pipes are used on buildings, particularly on the same by their artistic effect.

This curved form of the sides the size-thatis,

:brought together, forming a straightsections only being contemplated, a

sheet of the required size is first bent or angled by being passed through a break, forming it as shown in Fig. 4, t-o determine width of the sides 6and the location of the corners. The two parts vof the seam are also formed by crimping the edges of the sheet, after which they are pipe of a profile as indicated-in dotted lines in Fig. 2. l The pipe is then passed lengthwise through suitable forming devices, whereby the inwardlycurved form of the sides is obtained-and the seam closed and compressed. According to the degree of concavity, it may bemeeessary to repeat this operation until the desired depth-is obtained. After this the pipe is twisted to obtain the spiral shape of the sides and corners, which. is done by rotating more or less the ends of a section in oppositedirections. This twisting. operation decreases slightly the width of sides 6, giving corners 7 a tendency to approach each other, which,

until overcome, resists such twisting operation and makes it accordingly more difficult." f y hav ng sides 6, however, concave they are rendered less stiff than if straight, whereby the resistance to this tendency is--1essened and the twisting operation made more easy. W*itho11t these concave sides it is practically impossible to properly construct a pipe with twisted sides, as I have shown. I am aware of pipes having spiral corrugations produced and seam being straight.

wise complete pipe,

by pressure and stamping, the sides of pipe In my case the spiral shape is produced by twisting the otherw-hereby all parts of the latterthat is, sides, corners, and seamparticipate in the twisting operation and as:

sumo a shape accordingly. j

Having described my invention, I claim as new Y Y 1. .As a new article of manufacture, a straight sheet-metal pipe-section of polygonal profile, having all its parts, thatis corners 7 and sides '6 between them twisted to a spiral shape andthe sides 6 concaved. between the projecting corners 7, the whole being constructed of one sheet of metal which contains all the sides and the edges of which are connected by a lock-seam 8, such edges'being coincident with the edges of the sides 6,

so that when they are joined, the completed;

seam forms one of the corners 7 and is also spirally twisted.

2. A straight section of sheetunetal having a polygonal profile, and its corners -7 and sides 6 between them. twisted to a spiral' shape, the whole being constructed of one sheet of metal which contains all the sides and the edges of which are crimped to form the component parts of a lock-seam by which they are connected to being coincident with. the edges of the sides 6," so that when they arejoined the completed seam 8 forms one ofthe corners 7and is alsospirally twisted, the sides 6 between the corners being concaved, whereby angles are produced of which the one at the seam forms an internal abutment 9 as to one of thecomponent parts -of the seam which interlock here and against which abutment 9 the ex- "form the pipe, such. edges treme outer edge lO'of the other connecting part rests, whereby'the joining parts of the seam are prevented from slipping apart. In testimony whereof I hereunto affix my signature in presence of two witnesses.

, i JACOB F. WEITZEL. Witnesses: C. SPENGEh, ARTHUR KLINE. 

